Furnace braze cycle enhancement

Abstract

A method of decreasing a cycle time of a brazing process is provided. The method includes arranging each of first and second pairs of braze parts together, each of the first and second pairs of the braze parts having braze material interposed between the braze parts, stacking the first and second pairs of the braze parts to form a stack, interposing pyrolytic graphite (PG) between the first pair of the braze parts and the second pair of the braze parts in the stack and heating the first and second pairs of the braze parts to a brazing temperature to braze the braze parts of each of the first and second pairs of the braze parts together.

What is claimed is: 
     
         1 . A method of decreasing a cycle time of a brazing process, the method comprising:
 arranging each of first and second pairs of braze parts together, each of the first and second pairs of the braze parts having braze material interposed between the braze parts;   stacking the first pair of the braze parts to form a first stack;   stacking the second pair of the braze parts to form a second stack;   interposing multiple sheets of pyrolytic graphite (PG) between the first stack and the second stack; and   heating the first and second pairs of the braze parts to a brazing temperature to braze the braze parts of each of the first and second pairs of the braze parts together.   
     
     
         2 . The method according to  claim 1 , wherein the PG increases an effective thermal diffusivity of the stack and correspondingly reduces a cycle time required to braze the braze parts of each of the first and second pairs of the braze parts together. 
     
     
         3 . The method according to  claim 2 , wherein the PG increases the effective thermal diffusivity of the stack by about 3.0 times or more. 
     
     
         4 . The method according to  claim 1 , wherein the PG has a thermal diffusivity of about 500 mm 2 /s or more. 
     
     
         5 . The method according to  claim 1 , wherein the brazing temperature is between about 1050-1200° F. 
     
     
         6 . The method according to  claim 1 , further comprising interposing first and second stop-off layers between the PG and each of the first and second pairs of the braze parts, respectively. 
     
     
         7 . The method according to  claim 1 , further comprising encasing the PG in a metallic encasement. 
     
     
         8 . The method according to  claim 1 , further comprising layering PG on at least one of a top and a bottom of the stack. 
     
     
         9 . The method according to  claim 1 , further comprising at least one or more of:
 bending the PG around exterior edges of at least one of the first and second pairs of the braze parts; and   attaching an additional PG piece to the PG to abut with the exterior edges of the at least one of the first and second pairs of the braze parts.   
     
     
         10 . A method of decreasing a cycle time of a brazing process, the method comprising:
 arranging multiple pairs of braze parts together, each of the multiple pairs of the braze parts having braze material interposed between the braze parts;   stacking the multiple pairs of the braze parts to form multiple stacks;   interposing multiple sheets of pyrolytic graphite (PG) between adjoining ones of the multiple stacks; and   heating the multiple pairs of the braze parts to a brazing temperature to braze the braze parts of each of the multiple pairs of the braze parts together.   
     
     
         11 . The method according to  claim 10 , wherein the PG increases an effective thermal diffusivity of the stack and correspondingly reduces a cycle time required to braze the braze parts of each of the multiple pairs of the braze parts together. 
     
     
         12 . The method according to  claim 11 , wherein the PG increases the effective thermal diffusivity of the stack by about 3.0 times or more. 
     
     
         13 . The method according to  claim 10 , wherein the PG has a thermal diffusivity of about 500 mm 2 /s or more. 
     
     
         14 . The method according to  claim 10 , wherein the brazing temperature is between about 1050-1200° F. 
     
     
         15 . The method according to  claim 10 , further comprising interposing stop-off layers between the PG and each of the corresponding ones of the multiple pairs of the braze parts, respectively. 
     
     
         16 . The method according to  claim 10 , further comprising encasing the PG in a metallic encasement. 
     
     
         17 . The method according to  claim 10 , further comprising layering PG on at least one of a top and a bottom of the stack. 
     
     
         18 . The method according to  claim 10 , further comprising at least one or more of:
 bending the PG around exterior edges of at least one of the multiple pairs of the braze parts; and   attaching an additional PG piece to the PG to abut with the exterior edges of the at least one of the first and second pairs of the braze parts.   
     
     
         19 . A method of decreasing a cycle time of a brazing process, the method comprising:
 forming first and second stacks, each comprising multiple pairs of braze parts;   arranging the first and second stacks adjacent to one another;   interposing pyrolytic graphite (PG) between at least one adjoining pair of the multiple pairs of the braze parts in the first stack;   layering PG on at least one of a top and a bottom of at least one of the first and second stacks;   bending a PG end to extend between the first and second stacks along one or more of the multiple pairs of the braze parts in the first and second stacks; and   heating the multiple pairs of the braze parts of the first and second stacks to a brazing temperature to braze the braze parts of each of the first and second stacks together.   
     
     
         20 . The method according to  claim 19 , wherein the PG has a thermal diffusivity of about 500 mm 2 /s or more and increases an effective thermal diffusivity of at least the first stack by about 3.0 times or more and correspondingly reduces a cycle time required to braze the braze parts of each of the first and second stacks together.